remain motionless with robust preservation of
visual tracking in the form of smooth pursuit
movements (or optokinetic responses). Lim-
ited preservation of brief visual fixation can be
accepted in VS, but robust and consistent vi-
sual tracking as seen in akinetic mutism is ab-
sent in VS.
66
Patient 9–2
A 47-year-old right-handed man was brought to
the ICU with progressive somnolence and unre-
sponsiveness. Neurologic examination revealed
bilateral third nerve palsy, fluctuating bradycardia
with hypertension, and extensor posturing to pain.
The initial CT scan (Figure 9–5A) revealed a large
mass lesion centered on the mesencephalon with
surrounding edema. Intracranial lymphoma was
suspected and confirmed by biopsy. The patient
received cranial irradiation, IV steroids, and che-
motherapy. A posttreatment MRI (Figure 9–5B)
demonstrated resolution of mass effect with high
signal abnormalities within the upper mesenceph-
alon and hypothalamus. The patient appeared
alert but did not initiate communication. He occa-
sionally displayed sudden periods of agitated be-
havior. Responses to simple questions were mark-
edly delayed, but correct using yes and no answers.
Physical examination was notable for waxy flexi-
bility as well as rigidity, and spontaneous move-
ments were minimal and limited to the left upper
extremity.
EEG showed periods of frontal intermittent rhy-
thmic delta activity and mild generalized slowing.
An HmPAO single photon emission computed to-
mography (SPECT) scan revealed diffuse profound
frontal bihemispheric hypoperfusion (left greater
than right, see Figure 9–5C). The patient’s clinical
state did not improve prior to death from a systemic
infection.
Figure 9–5. Akinetic mutism seen in Patient 9–2. (A) Computed tomography scan demonstrating large mesencephalic
mass with surrounding edema. (B) Series of magnetic resonance axial images following treatment with steroids and
reduction of mesencephalic lesion. Middle image shows high-signal abnormalities in the ventral midbrain. (C) Single
photon emission tomography imaging demonstrates diffuse cerebral hypoperfusion with relative sparing of cerebellar
blood flow. (Images courtesy of Drs. Ayeesha Kamal and N. Schiff.)
362
Plum and Posner’s Diagnosis of Stupor and Coma
Autopsy of brain was normal except for the mid-
brain, hypothalamus, and left paramedian thala-
mus, which showed infiltration of lymphoma cells
and necrosis in the midline of the midbrain ex-
tending rostrally into the left thalamus to involve
the intralaminar nuclei and surrounding tissue.
Late Recoveries From the
Minimally Conscious State
Word-of-mouth stories and news reports some-
times claim dramatic recovery from prolonged
coma or VS. Invariably, these reports generate
wide public interest and much confusion con-
cerning the difference between coma and VS,
as well as between diagnosis and prognosis.
The Multisociety Task Force
64,65
examined 14
cases from the media and found that the ma-
jority of these ‘‘late’’ recoveries from VS fell
within their guidelines (i.e., less than 3 months
following an anoxic injury or 12 months fol-
lowing a traumatic brain injury in an adult).
Nonetheless, as noted above, a few rare, well-
documented late recoveries underscore the
statistical nature of the guidelines for prognosis
of permanent VS. However, most reports of
late recovery from ‘‘coma’’ involve very late
transition of MCS patients to emergence (see
page 373). There are no data to allow guide-
lines for the expected duration of MCS. Some
MCS patients harbor significant residual ca-
pacities as demonstrated by wide fluctuation of
cognitive function.
91
The term minimally con-
scious state seems most appropriate; alterna-
tives include minimal responsive state and
minimal awareness state.
92
Minimal respon-
siveness as assessed at the bedside may belie
considerable cognitive capacities without fur-
ther evaluation of etiologic mechanisms, in-
cluding normal cognitive function as present in
the locked-in state, discussed below.
LOCKED-IN STATE
A related and important issue is late recovery
of consciousness in patients with severe motor
and sensory impairment leading to the locked-
in or partial locked-in state (condition with
severe motor disability approximating the tra-
ditional definition). The locked-in state is not
a disorder of consciousness, as reviewed in
Chapter 1. Nonetheless, because most cases of
the locked-in state are due to a pontine injury,
it is common for patients to experience an ini-
tial coma (see
93
for an example) or to respond
inconsistently during the initial period of the
injury similar to MCS. In a survey of 44 locked-
in patients, the mean time of diagnosis was 2.5
months after onset; in more than one-half of
these cases, a family member and not a physi-
cian first recognized the condition.
94
Further-
more, investigators working with locked-in
patients often report early counseling of with-
drawal of care either because of an incorrect
diagnosis or based on physician attitudes
without a careful and vetted informed consent
process that includes a review of the available
information on quality of life obtained from
surveys of patients in this condition.
94,95
While
it is quite reasonable to doubt that most people
would want to trade a normal existence for that
of a locked-in patient, the important question
is whether a locked-in patient would rather
live or die. Quality-of-life assessments admin-
istered to locked-in patients provide a source
of information for patients and families as
do written first-person accounts, several of
which have become well known.
96
Doble and
colleagues
95
reported on 5-, 10-, and 20-year
survival (83%, 83%, and 40%, respectively) and
quality of life in 29 patients. Among several
notable findings, these investigators found that
12 patients remained living 11 years after the
study onset; seven of these patients described
‘‘satisfaction with life,’’ five were noted to ex-
hibit occasional depressive symptoms, but none
held a DNR order. Leon-Carrion and associ-
ates
94
described quality-of-life measures in
more detail in their survey of 44 locked-in pa-
tients (Table 9–13). The majority of these pa-
tients (86%) described a good capacity to
maintain attention, nearly half (47%) described
their mood as ‘‘good,’’ most (81%) met with
friends at least twice a month, and 30% could
maintain sexual relations (Table 9–13).
Quality of life was also assessed in 17 chronic
(i.e., more than 1 year) locked-in patients who
used eye movements or blinking as a princi-
pal mode of communication, lived at home,
and had a mean duration of locked-in state of
6 years (range 2 to 16 years).
97,98
Self-scored
perception of mental health (evaluating mental
well-being and psychologic distress) and per-
sonal general health were not significantly
Consciousness, Mechanisms Underlying Outcomes, and Ethical Considerations
363